Spatial coherence of an optical turbulent beam in a biased photorefractive crystal due to the spatiotemporal modulation instability

OPTICS COMMUNICATIONS

卷:278

Article

Sheu, Fang-Wen ; Shih, Ming-Feng

关键词: interference;    coherence;    self-focusing;    optical instabilities;    pattern formation;   

DOI  :  10.1016/j.optcom.2007.06.002

来源: Elsevier

【 摘 要 】

We report the experimental observation of the dynamic pattern formation of a broad coherent light beam in a biased photorefractive crystal due to the spatiotemporal modulation instability. When the nonlinearity exceeds a specific threshold, the coherent light beam not only breaks up into light spots due to the modulation instability but also fast fluctuates both spatially and temporally, forming an optical turbulent beam, which behaves as a quasi-homogeneous speckled beam or a partially incoherent beam. We investigate the spatial coherence property of an optical turbulent beam from the visibility of the averaged double-slit interference fringe. We also numerically demonstrate the visibility variation of the instantaneous interference fringe of an optical turbulent beam. (c) 2007 Elsevier B.V. All rights reserved.

【 授权许可】

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